U4076B-FL

U4076B Three-Tone Ringer for Telephone Sets Description The three-tone ringing integrated circuit U4076B, in conjunction with a piezo transducer or loudspeaker replaces the normal electromechanical telephone bell. It is operated with the ringing current from the exchange. There is also a possibility of operating the IC with the dc supply voltage, being developed for large operating range. The integrated circuit is overload protected. Features D Three-tone ringing sequence with 800 Hz, 1067 Hz and 1333 Hz D Clock oscillator with ceramic resonator or LC series cct possible D Sequence frequency adjustable between 2.5 Hz and 25 Hz D Input protective diode D On-chip rectifier bridge D Protection circuit against ringing in a parallel circuit D D D D D Adjustable volume Push-pull output stage Piezo transducer or loudspeaker connection Common input for frequency and call recognition Reduced pulse duration for electromagnetic transducers Benefit D Suitable for German Post Office Specification, FTZ 121671 Pfl. 3, edition dated 24.03.82 22 m F 2.2 k W a ~ ~ b 0.8 m F 4 7 (5) 6 (7) 600 kW 10 (11) 43 kW 8 (9) 4.7 nF 9 (10) (15) 13 Ground: output signal Open: output signal (8) Supply 5 (6) Level monitoring Tone sequence oscillator Divider 32:1 Tone signal generator 11 Reset a (12) 100 kW log 12 (13) 96 ms 127 ms Frequency monitoring Frequency Three state Divider 32:1 Divider 14:1 Clock signal generator 3 (3) 93 7792 e Reset b 2 (2) 455 kHz Divider 128:1 Divider 2:1 RL 14 (1...